The z1d.xlarge pairs 4 vCPU with 32 GiB of RAM, the 8.00 GiB-per-vCPU ratio that marks a memory-optimized instance. In the name, "z" is high clock frequency, "1" is the generation, "d" marks local NVMe storage and "xlarge" is the size within the z1d family. It runs on Intel Xeon Platinum 8151 at 4 GHz, and AWS introduced it in July 2018. z1d is the current generation of the z family, so there is no newer AWS size to migrate to. mh.vs1.large on Rackspace Spot lines up one-for-one: 4 vCPU and 32 GiB, about 94% below the US East (N. Virginia) on-demand rate.
Match qualityNo local disk
z1d.xlarge comes with 1 × 150 GB NVMe SSD attached to the machine. Rackspace Spot nodes use network storage only, so that disk does not come with it.
If you were using the local disk as fast scratch space — temporary files, a local cache, an index — you will need a persistent volume or object storage instead, and both are slower to read. If it was just extra space you never depended on, nothing changes.
